Sintering process for the recovery of metallic oxids from flue-dust.



e. F.. DOWNS. SINTERING PROCESS FOR THE RECOVERY OF METALLIC OXIDS FRO M FLUE DUST Patented Feb. 2, 1915.

3 SHEETS-SHEET 1 APPLIUATION FILED AUG. 6. 1914.

Luff/12552;,

G. P. DOWNS. SINTERING PROCESS FOR. THE RECOVERY OF METALLIC oxms P APPLICATION FILED AUG. 6, 1914.

ROM FLUB DUST. 1,127,209.

a sums-sum Illll H IIIIHII' IIIIIIIIIHH Patented Feb. 2, 1915.

G. F. DOWNS. SINTBRING PROCESS FOR THE RECOVERY OF METALLIC OXIDS FROM FLUB DUST.

APPLIUATION FILED AUG. 6, 1914. 1,127,209.

3 SHEETS-SHEET 3.

Patented Feb. 2, 1915.

UNITED STATES PATENT OFFICE.

Gnomes Downs, 01 BUFFALO, NEW YORK.

SINTERING PROCESS FOR THE RECOVERY OF METALLIC OXIDS FROM FLUE-DUST.

Specification of Letters Patent.

To all whom it ma cont-em:

Be it known that I, GEO G F. lrloi'vns, a citizen of the United States, residing at Bufialo, 'in the county of Erie and State of New York, have invented certain new and useful Improvements in Sinterin" Processesfor the Recovery of. Metallic Kids from Flue-Dust, of which the renewing? is a spamfication. c

My invention relates to a sinteriii'g prodess, and more partionlarly to an improvise process of treating aw blast furn ce fine.

*guantity of comminuted material, lznovvii as ue dust, containing fine iron oi'e, coke a m limestone, is carried 'oiit of the by the Waste 'gase"s and Collected. It heretofore been proposed to eg iememaeiiiis flue dust in various ways; but the most effective method has been to sliliject the fine dust, While "assing in a fnrfiacei to the eoiidii'io of heat. pioeu e'e by sea, [6i fnel blov'v'ii in at the delivery 'e'fid ofthe v r"- nace.

My invention relates to this general method of treatment, and 1 pro 'ose in y to utilize the heat fronl t 'e coifihiisl'tlon iii the particles of carbonin thefin directly upoh the iron-beariii nitteiial stfo a erate then; into a 'si l'itgr; t6 b'anse I e ter'ing to take pl'c te witii'oiit the aeeitieii er fuel or binding material firedu'oiri" violent a'gitation; of the fine d'list'd-iirin period of conihnstio'i'iof its Games content.

This ii-mess, w j independent of s'pecific apfiai'attls for ca'fiyriiit; fie has been suc essfully carried otit i-fi at afi rams such isfshowriin n'di 4 lif cation rem-y .fnriilc' kilns, lees miss, 1 14, seiiai no, 834,3B9 fii a 'c'h. 11g iiiiif one accesories and aidjfi'stfiien't'i-e To? tempera tire; am; eage watt-61" We determined by me. Tiieieiofi; I a m, ifi

describing and in iseiating my tness, fifein the assage I it is ag'tated by being carried up on one side fer to use apparatus similar in character to that Shawn in said apfilicatio'n. Of course other apparatus may be adopted for carrying out my process, but said apparatus firovides means for eficting three essential features of ypro ess, nainely, continuous s l'nt'rin sifply of air to produce the reqnii ed eat ioni coinldilstion of the carbon content without the addition of other fuel, and violent agitation of the flue dust durlilg the peiiqd of 'coihbnstion of said carbon content. y

llnthe drawings illustrating my process, in which characters of reference indi- Cate corresponding parts, Figure 1 is'a longitndih al, vertical section of a furnace provided With the inea'ns for carrying out rocess. Fig.2 is an enlarged detail side elevation of the twyei' section of the furiiiic-"e. Fig. as an enlarged section of one of the' manifolds employee. Fig. 4 is a section (iii azw of Fig. 2. 5 is a section on 1H 0' Fi Rtiei iii' to the drawings, 1 indicates a weary kiln iii the form oi a hollow cylih' d er, snitably lined 'W'itli refractory in'at'erial. Said kiln is mounted on rollers 2, that it m item freely; The cylinder is rotated By an desired Well-known means. The furnace of kiln 1 is inclined slightly for this process from its inlet to its ontlet end, so as to inslire the travel of the fininttir'e through the kiln.

iii epeia'iiaii' the kiln is iptaied sii wlygiiid of the material therethrougli,

(if the ilnand falling. hack to :e' liottom. By varying the speed of rotation of the the size of the lm'nps or masses: canb 'Jgo'vr'nerl. The iipf ei end of the kiln 1 o ens ihtoa chaniber 3; inroyided with a sjta k 4 for the disiiosalof gases and products of coiiiibusti-on'. E'zitendihg through the be a is a iee chute wiiie a continnonsly dischar' es the nia'teiial to be treated into the 5' em dithe rim. T e weer age of the E1 h l rotates a stationary .ho otl sti'h c; ere ibiifit d 6h w ee sf sofihai It m Be feafiil tiered. to and; fr m the bin; and mai th an eer e; h f j h c ei ma mils passing through the kihi are disc ar ed. This hood structu e is pre- Patented Feb. 2, 1915.

eieimcient supply of air to start combustion when starting the operation. Adjacent to this tube 7 is a tube 8, leading from the blower 9, which may be employed if occasion de- -mands for augmenting the supply of air furnished by t e twyers.

It has been found in practice that there is a tendency for the sintered material to adhere to the walls of the furnace, and to prevent this a water-cooled poker 10, having a reciprocatin motion, is employed at the lower end 0 the furnace. This poker 10 is suitably suspended to a swinging hanger and means provided for imparting to the poker a reciprocating motion. ThlS action of the poker scrapes the linin and prevents the sintered material from a hering to the walls of the kiln and dislodges any material which may become attached to the walls of the kiln, thereby promoting the passage of the material therethrough.

12, which lie parallel with the axis 0 In the walls of the kiln, near the discharge end, are air inlet openings, which is herein referred to as the twyer area, equip ed with air supply twyers 11, extending rom the manifold pipes l2,which communicate with the blower 13.

14 is a circular manifold head, or u standing circular plate, which is preferab y built up of segments and clamped or secured to the kiln in any desired manner. Secured in flanged openings in this circular manifold head 14 are the manifolds or air piples t e cylinder. These manifolds are arranged,

preferably, symmetrically about the kiln,

and may be of any desired length or frequency, accordin to the material to be treated. The en s of these manifolds o posite the ends secured to said manifo (1 head are closed. Leading from the manifolds are ni ples 15, which connect with cross-connections 16, which connect with the 1 twyer pi es 11, which pass into the interior of the cy inder.

Mounted upon supports 17 are brackets 18. Rigidly secured to these brackets is an annular late 19, referably built up in segments, w ich sets ace-to-face with the man1- fold head 14. This plate 19 is held up to the face of the manifold head so as to make a a substantiall gas-tight contact by means of spring-hel OllPS 20. In this manner the plate 19, which is non-rotating, sets up against the manifold head 14 and over the open ends of the manifolds 12, except as resently described. These contacting suraces, the one fixed and the, other rotating, are well removed from the interior of the furnace and may, therefore be readily lubricated.

Mounted gas tigl t upon the plate 19 is a wind-box 21, whic for the urposes of this process, is a segment of s cient length to cover or include one or more of the manifold kiln to the twyer area has ends substantially at all times. The ortion of the plate 19 covered by this windbox is slotted to permit the passage of air from the wind-box to the manifolds as they come by rotation within the area thus formed. Connected with the wind-box 21 is a duct 22, which supplies air under pres sure from a blower 13.

It will be seen that the foregoing is an abbreviated description of the apparatus shown in my said pending application, Serial No. 834,399, and for further detailed description ofthe same reference is had to that specification.

My novel process, which may be carried out by such or other adequate apparatus, is as follows: Flue dust is fed regularly and continuously under control throu h the ipe 5 into the open end of the ki n 1, which is under rotation. A supply of powdered coal or coke is introduced is used, therefore, only to bring the interior of the kiln to a proper sintering tem perature and to assist in maintaining this temperature, if it is found that the necessary temperature resulting from the combustion of the coke in the dust will not be sufficient to conduct the sinteringprocess. This results in great economy in fuel consumption, which is one of the objects of the process. Now the heat absorbed by the mixture lowers the temperature in the u per art of the kiln 1 to about six hun red egrees, Fahr. The mixture, therefore, moves along through a gradually increasing temperature and a small part of the coke w1ll be consumed, but there will remain most of the unconsumedcoke when it reaches the twyer area. In this area, as the air is su plied.

through the twyers, rapid combustion of the remaining coketakes' place and the metallic content is sintered, taking the form of lumps or nodules. And herein lies the important and difierentiatin features of my improvements. The flue ust in its continuous progress from the upper end of the ad its tem erature raised to the combustion point 0 the carbon content, but very little of the carbon has actually been converted and little sinterin has taken place. But when this heate continuously-traveling mass reaches the twyer area it is not onlysu plied with suflicient air to complete the com ustion, but

Ill

with twyer blasts from the lower portion ll.

of this area Which cause violent agitation and continuous bombardment of the upper portion of this area by the flue dust while its carbon content isv in process of burnifigwhich agitation and bombardment res ts in the mechanical union of the metallic and binder content while the chemical process of combustion is aflording the necessary heat to permit such mechanical action. After the sintered material passes the twyer area, it continues by gravitation and'rotation to the lower end of the cylinder, where it passes to a receptacle (not shown) in 'WhlOl]. it may be cooled or conveyed away as desired. It will thus be seen that the material is gradually and thoroughly heated under constant movement and mlxing, until by the time it reaches the twyer area, it is at a temperature where the contained carbons Will readily combine chemically with the oxygen there supplied, in this area the most intense heat and fuslng action occurs and the actual agglomeration is accomplished here, as above described, instead of being distributed through a considerable length of the kiln.

Having thus described my process and the method of carrying the same into eflect, I claim l. The herein described process of reducing flue dust which consists of passing flue dust in a continuous mass through a rotat- 4 ing 0 lindrical kiln or furnace slightly incline from the horizontal and subjecting the flue -dust to blasts of air through nu merous twyers so regulated that the air is admitted underneath the flue dust and violently agitates' and lifts the flue dust in passing through it and creates suflicient heat through the combustion of the carbon contained in the flue dust with the oxygen contained in the air to sinter or nodulize 2. The herein described process of reducing flue dust which consists of progressively heatin a continuous discharge of flue dust and de ivering it to a twyer area at a temperature substantially that at which the carbon content will combine with an oxygen supply to cause thorough combustion, then blasting into said twyer area and beneath the heated flue dust air under pressure to violently agitate said flue dust and to supply the necessary oxygen for combustion, whereby, while the chemical operation of combustion is taking place, the metallic and binder content of the flue dust are mechanically combined in a heated state by said agitation.

GEORGE F. DOWNS.

Witnesses:

Rrommn Somme, D. H. HARPER. 

